Photographic shutters



Sept. 12, 1961 E. HAHN ETAL 2,999,437

PHOTOGRAPHIC sHuTTERs Filed 001;. lO, 1957 3 Sheets-Sheet 1 Sept 12, 1961 E. HAHN Erm. 2,999,437

PHOTOGRAPI-IIC SHUTTERS Filed OOC. l0, 1957 3 Sheets-Sheet 2 lIIIIlllIlllllllllllllllllllllllIIIIIIIIlIllllllllllllllIIIIIIIIIII!wml lNvENToRs imc# /J/:HN

Sept. 12, 1961 E. HAHN ETAL PHOTOGRAPHIC SHUTTERS 5 Sheets-Sheet 5 Filed Oct. l0, 1957 s wm l MH wm. mm E r 2,999,437 Y PHOTOGRAPHIC SHU'ITERS Erich Hahn, Werner Hahn, and Rolf Noack, Dresden, l(ernany, assignors to VEB Kameraund Kinowerke res en Filed Det. '10, 1957, Ser. No. 689,428 9 Claims. v(Cl. 95-410) This invention relates to photographic shutters and more particularly to shutters having setting means for setting the exposure factors, ie., the factors determining proper exposure, which setting meansare functionally and operativelycoupled with each other and function as addition quanti-tiesor magnitudes in a summa tion' mechanism.

Such measures andlmechanisms are necessary in cameras, wherein either aY separatel light value scale is provided on the shutter, or wherein the setting means or members of the ,shutter are operatively connected with an exposure meter. n

The hitherto known mechanical connections of setting means Vfor the` exposure factors for the purpose of adding exposure factors to arrive at a summation value determining the exposure consisted vin diiferential gears which inV turn were composed 'of spur gears, bevel gears or 'worm' gears.: 'It is obvious that the provision of mechanisms comprising-such relatively complicated elements resulted in considerable additional expenditure, thus making su'ch cameras considerably,4 more expensive. Further, the known arrangements-.of th'e kind referred to', were not suitable and, generally,fdid not fulfill the requirements for jcameraswhereinit `is desired to use interchangeable lens attachments.

Accordingly, it is an object of this invention to provide a simplaeicient :and inexpensive arrangementof the kindreferredto by means of which it is rendered possible to bringthe sum of .the exposure factor values or the individual addition `magnitudeV values into register with the brightness tor lightv value reading thathas beenascertained, for example, bymeans of an exposure meter'orthe like.V Y i A further object ofthe present invention is to provide an arrangement "of theY kind `referred to, which is usable in or adaptable for cameras with interchangeable lensv attachments.

Q In accordance with this invention the above mentioned objects are attained-by having the setting means orv rings forfthe exposure factors-engage eachother by means of screwor-worm shaped cammechanisms so that upon ron tation'of the rings; relative toY each other, a movement occurs inf a portion yof the cam-mechanism, said movementjbeingindicate'cl by a vector which extends in a direction perpendicular to the plane 'of rotation and acts on an indicating means, e.g., a pointer or the like device. Theaction or effect of lthis vector canI be utilized both for lindicating the'- light value `cna common light value scale of the camera,-or also directly for controlling or actuating a follower'vorpointer offan exposure meter.

l. The invention'willfbje more fully understood and other objects and advantages of ythe invention'will become apparent from thef following description and the drawings, inwhich: l 1

i FIG. 1 is a diagrammatic presentation of the principle involved in the invention; i

FIG. 2 is a first embodiment of an arrangement in accordance with the invention;

FIG. 3 is a partial sectionuof FIG. 2);

FIG. 4Y shows a second embodiment of the inventive arrangement; A`FIG. 5 shows the construction of a push-rod employed in the inventive construction;v

United StatesPatent ice FIG. 6 shows a still further embodiment of the inventive arrangement; and

FIG. 7 shows an interchangeable lens attachment to be used in connection with the inventive arrangement.

Referring now to the figures and in particular to FIG. 1, the differential or compensating mechanism according to this invention is constructed as a cam mechanism and is based on the principle of oppositely arranged wedges. As will be readily gathered, the value or distance X, indicated in FIG. 1, will not change and thus will be constant, if both wedges 1 and 2 do not move with respect to each other, i.e., if wedges 1 and 2 move jointly in the direction of arrow 3. Arrow 3 indicates the direction of the primary movement. However, the value or distance X will be changed as soon as the wedges f1 and 2 are moved relative to each other in the direction of the arrow 3. In the latter case, there occurs a movement of one wedge with respect to the other indicated by vector V in the direction of rthe arrow 4, that is in a direction perpendicular to the primary movement which causes a secondary movement of the wedge 1, the latter being freely movable in the direction of the vector V.

This principle is constructively embodied as follows:

The iirst embodiment of la constructional design of the principle elucidated above is shown in FIGS. 2 and 3. A'time setting ring 6 and a diaphragm setting ring 7 are rotatably mounted concentrically relative to a shutter housing 5 (FIG. 3). The rings 6 and 7 are operatively in engagement with each other by the provision of a `screw 9 arranged on the time setting ring 6, which screw 9" projects into and engages a slot 8 in the diaphragm setting ring 7.- `Due to the action of a psring 2i), a push Yrod or plunger :10 (FIG. 3) is urged against front surface 14 of the diaphragm setting ring 7, which push rod 10 coacts with a follower 1'1 of an exposure meter 12. The diaphragm setting ring 7 is operatively connected with a laminated diaphragm ring structure 1S by means of a screw 16, said screw 16 engaging in a groove 17 of the diaphragm ring 18.

Upon rotating the setting rings 6 and 7 simultaneously, as will be'the case when the values for the exposure time and the diaphragm setting are to be adjusted or set in the same proportion or ratio, that is under retention of the same light value, the push rod 1G merely slides along the surface 14 without affecting or actuating the follower 1-1. Such simultaneous rotation of the setting rings 6 and 7 may be facilitated by the provision of a coupling known per se which coupling consequently is not shown lor described. dt is only generally indicated by an ele.-

ment or knob 19 (FIG. 2) which is manually actua-ted and by means of which this coupling may be actuated.

If, however, only one of the two setting rings 6 or "i is moved, aA displacement of the diaphragm setting ring 7` in axial direction due to the screw-slot guide 9 and 8 occurs, resulting in yanA actuation of the push-rod t1l) and consequently of the follower 11. As soon as the follower 11 due to this secondary movement is in register with a pointer or indicator 15 of the exposure meter 12, Athe exposure factors are properly adjusted and set. ln other words, the pointer 15 of the exposure meter 12 indicates the proper light value in accordance with which the setting means should be set and the follower 11, operatively engaged with the setting rings 6 and 7 through the element 10 is moved until it is in register with the pointer 15, whereby the proper adjustment has been made, since the setting means 6 and 7 constitute the exposure factors. It is obvious that it is of no importance which one of the setting members 6 or 7 is provided with the slot 8 and which one with the screw 9. It is, of course, possible to reverse the arrangement, as for example, shown in FIG. 4. In FIG. 4 an embodiment is come? shown wherein a time setting means 6 is provided with a slot 8 while a diaphragm setting ring 7 is provided with a pin 9.

In order to facilitate the adaptation of the exposure meter i2 to the shutter and, in particular, to .the front surface ifi, the push-rod 10 is advantageously `'constructed of two parts l and itl (see FIG. 5). A sleeve or socket i3 receives one end of both parts whereby the length of the push-rod Cid can be readily adujsted according to the requirements.

in accordance with the embodiment shown in FiG. 6 a shutter housing 2i is provided with an exposure time setting ring 22 which is coupled with a gear 23. Further, on the shutter housing 2l, there is rotatably mounted a lens fitting ring 24 which selves the purpose of securing interchangeable lens attachments, as for exam- Iple, a lens attachment 25 as shown in FIG. 7. The lens attachment Z is removably attached by known means (not sho-wn) to the tting ting 24 (see FIGS. 6 and 7). A setting ymember 26 for a diaphragm structure 32 of the lens 25 is mounted within a groove in attachment Z5 and is provided with a control cam 27. A rod traverses the shutter housing 21 in axial direction which rod comprises a front threaded portion 28 and a rearthreaded portion 29?. The rontthreaded portion 2S has an outer thread 3d and the rear threaded portion it@ has an inner thread 31, whereby the entire rod can be extended or shortened in telescopic manner. The front threaded portion 2% carries a p iniont which meshes with the gear 23 while therear threaded portion 29 is provided with a further pinion'. 3.4 which meshes with an interior toothing 35 of a setting ring 36 retiecting the lm sensitivities.

The length of the pinions 3,3 and 34 is adjusted in such a manner that, in spite of axial displacement Vdue to the action of the previously mentionedfvector V, they remain in engagement with the gears 23 and 35. A spring 37 tends to urge the rod 28, 29 into positive engage-ment with the cam 27. A feeling bolt 3S which is arranged on the rear threaded portion 2 9 is in operative connectionwith a measuring mechanism known per se, which in the present embodiment is em-bodied by afollower 3 9 which latter is biased by a spring 40. The follower 39 is brought into register in known manner with a pointer 41 of the measuring mechanism.

The mode of operation of the last mentioned embodiment is the following:

The arrangement is tirst adiusted to the sensitivity o f the film to bey used Iby turning ring 36r to the proper value, whereby the threaded portion 29 is turned through the toothing 35. This rotational movementcauses a corresponding -length adjustment of the rod 2 8, 29 through the thread connections 30, 3x1. In this manner, the exposure factor resulting from the film sensitivity, ie., the

value corresponding to the lm sensitivity has been added to the rod length.

Finally, it is necessary to make a-properselection of exposure time and diaphragm value in :such a manner Athat the still missing addition factors vare expressed in the form of corresponding length alterations of .the rod 218, 29, so that the position of the Vfollower 3 9 can be brought into register with the lposition of the. pointer 4l of the measuring mechanism. v

For the purpose of elucidating this example, let u s assume that the operator desires to obtain a certain depth of held. Consequently, the desired diaphragm v alue is rst set by turning the, diaphragm setting vring 26 to .the desired value, and the rod 23. 2 9 Willbe Vaxially displaced through the cam 27. T he further @length -adiustvment of the rod required vfor completing the 'light value which has been indicated by the pointer 4 1, iis imparted to the rod by turning the exposure time setting .ring 22, whereby the gear 2,35` which kis lconnected with the setting ring 22 transmits its rotational movement to thepinion '33 ofthe front threaded por-tion 28. Due-to the' Ithreaded connections 30, 31, there occurs again an alteration in telescopic manner inthe length of the rod composed of the threaded portions 28 and 29.

It is obviously also possible to make the follower 39 act on a light value scale provided on the shutter so as to avoid the buil-ding in of an exposure -meter into the camera. The mode of operation of the summation mechanism, of course, would not be changed thereby. On the other hand, the arrangement which in the present case is adapted to serve the purpose of setting the exposure factors comprising exposure time and diaphragm value could also serve the purpose for setting the diaphragm value and the distance value, s o as to eliminate the necessary mathematical calculations required for ash exposures.

. We claim:

l. In a camerav having a housing, a photographic exposure control mechanism comprising Iirst exposure lfactor setting means including a first rotatable setting ring, second exposure factorsettingmeans including a second rotatable setting ring, a cylindricalv cam surface on one edge of said rst ring, a control rod extending transversely to the plane of said vtirst ring, means for biasing said control rod against said cam surface for' axial motion vin response to rotation of said first ring, a control sleeve threaded to the free end of said control rod for axial movement thereof due 'to axial movement of 'said control rod, said second setting means including coupling means connecting said control rod to said second ring'for .rotating said rod, means for controlling the rotation of said control sleeve whereby upon rotation vof said rod said sleeve is axially moved, 'and indicating means responsive to the position of .said sleeve, for indicating the composite positions of said setting means.

2. In a camera, a photographic exposure control mechansm according to claim 1, wherein said coupling means comprise a pair of gear wheels in meshed engagement, one of said wheels being coaxially mounted with said control rod and the other gear wheel being `coaxially mounted with said second setting ring and connected thereto.

3. In a camera, a photographic exposure control mechan ism according to claim 1' further comprising a third setting ring, said third ring having circumferentially. d isposed gears at its inner periphery,` and wherein said movable vshaft has circumferentially disposed .gears at its outer periphery, said shaft and said third'setting being in meshed engagement.

4. LAn apparatus as in claim 1, wherein said rotation controlling means include a third setting ring for .establishing a desired light value setting, and gear means connecting said third ring to said sleeve for rotation ofsaid sleeve with said third ring so to ,axially move said sleeve with respect to said rod, and wherein said indicating means include an onposition indicator responsive to the axial position of .said sleeve whereby upon said third ring being set to a desired light value, said first and second rings can be adjusted to cause .said sleeve tto move an amount suicient for Asaid indicator vto read the `onposition, and thus produce a composite ysetting of the exposure -factors corresponding `to the selected light. value.

5. An apparatus as in Claim 1, Whereinsaid coupling means include gear `.means .on .the outer surface of said rod and connected to. .said second ring for transmitting rotary motion v from said ,second ring to said threaded sleeve whereby said sleeve is axially moved with respect to said rod and imparts 4motion to said indicating means.

"6. An apparatus as in claim `1, wherein said rst setting means include an aperture control in said housing for response Ato the position of said rst setting ring.

7. An apparatus as in claim 5, wherein said second setting means includes a shutter time control.

8. In a camera, photographic exposure control apparatus comprising a housing, first exposure factor setting means including a first ring rotatably mounted on said housing, second exposure factor setting means including a second ring rotatably mounted on said housing coaxial with said first setting ring, rotatable-cylinder cam means connected to one of said setting rings and responsive to rotation thereof, follower means in engagement with said cam means for axial motion parallel to the axes of said rings and connected to the other of said setting rings for rotary movement in response to rotation of said other ring, sleeve means threadably connected to said follower means for axial movement in response to rotary and axial movement of said follower means and means operatively associated with said sleeve means for indicating the composite light values set in the exposure mechanism of said camera.

'9. In a camera, a photographic exposure control mechanism comprising a shutter speed setting ring rotatably mounted in said camera, a lens aperture setting ring rotatably mounted coaxial with said shutter speed setting ring, a cylinder cam surface connected to an edge of one of said setting rings and responsive to rotation thereof, a follower pin 4in engagement with said cam surface movable transverse to the plane of rotation of said rings, a plurality of threads on said pin, a threaded sleeve on said pin axially movable as a result of rotation of said sleeve and longitudinally movable with said pin, gear means secured on said pin `for rotating said pin in response to rotation of the other of said rings, and means responsive to the axial movement of said sleeve for indicating the total light value set into the exposure control mechanism.

References Cited in the le of this patent UNITED STATES PATENTS 2,117,429 IKuppenbender May 17, 1938 2,186,616 Mihalyi Jan. 9, 1940 2,252,573 Leitz Aug. 12, 1941 2,467,946 Rossman Apr. 19, 1949 2,612,091 Weiss Sept. 30, 1952 2,887,026 Rentschler May 19, 1959 FOREIGN PATENTS 756,282 Germany Feb. 23, 1953 1,120,299 France Apr. 16, 1956 

